LED TO THESE ARRESTS WAS FROM THE PUBLIC. TONIGHT WE'RE LEARNING MORE ABOUT THE THREE VICTIMS OF CARBON MONOXIDE POISONING IN PLAISTOW. FRIENDS SAY ALL THREE OF THEM WORKED TOGETHER AND HAD JUST RETURNED HOME FROM A CONVENTION. POLICE WERE CALLED AFTER THE GROUP FAILED TO RETURN PHONE CALLS. THE FAMILY OF THE MAN WHO OWNED THE HOME IN PLAISTOW WHERE THREE PEOPLE DIED FROM CARBON MONOXIDE POISONING SPENT PART OF THURSDAY CLEARING OUT HIS THINGS. THE BODY OF 33-YEAR-OLD KIRK WALSH AND TWO OF HIS ROOMMATES, 47-YEAR-OLD MARY ANN AND 28-YEAR-OLD JOHN ADAMS JR. WERE FOUND IN THIS HOME ON TUESDAY. A FOURTH PERSON KEITH SMALL IS IN CRITICAL CONDITION AT MASS. GENERAL HOSPITAL. THE GROUP WORKED TOGETHER AT A DIRECT SALES COMPANY CALLED ATN. THEY HAD JUST RETURNED HOME FROM A BUSINESS TRIP. MONDAY THEY WEREN'T RETURNING CALLS, NOBODY WAS ABLE TO GET A HOLD OF THEM. AND THAT WAS A LITTLE SUSPICIOUS BECAUSE THEY ALWAYS RETURN CALLS. THE AUTHORITIES WERE CONTACTED SOMETIME TUESDAY. WALSH WAS A REGIONAL DIRECTOR FOR ATN, A YOUNG PROFESSIONAL ON THE RISE, WELL LIKE BID NEIGHBORS IN THIS COMMUNITY ON CENTER CIRCLE. NICE GUY, ALWAYS HAD PEOPLE OVER WITH HIS BUSINESS. LIKE THE NEIGHBOR SAID, ALWAYS PLAYING VOLLEYBALL, LET MY DAUGHTER SWIM AND A COUPLE OTHER KIDS HERE. INVESTIGATORS SAY A PROPANE HEATING SYSTEM WAS THE SOURCE OF THE CARBON MONOXIDE. IT'S A TRAGEDY THAT HAS NEIGHBORS TAKING A CLOSER LOOK AT THE SAFETY OF THEIR OWN HOMES, AS FRIEND PREPARE TO SAY GOOD-BYE TO A YOUNG MAN WHO HAD SO MUCH PROMISE. THE